#include<stdio.h>
#include<math.h>

int main(void)
{
	double a,b,c;
	double area,perimeter,s;
	
	printf("Enter 3 sides of the triangle:");
	scanf("%lf %lf %lf",&a,&b,&c);
	
	if ((a+b>c) && (b+c>a) && (a+c>b))
	{
		 s=(a+b+c)/2;
	     area=sqrt (s*(s-a)*(s-b)*(s-c));
	     perimeter=a+b+c;
	     printf("area=%.2f;perimeter=%.2f\n",area,perimeter);
	}	    	     
	else 
	{
		 printf("These sides do not correspond to a valid triangle\n");
	}
		
    return 0;		     
}
